Add plumbing for accessing latest country in variations service in Java

components/variations/service/variations_service.cc

Index: components/variations/service/variations_service.cc
diff --git a/components/variations/service/variations_service.cc b/components/variations/service/variations_service.cc
index 34be822271ed3f41ccd1feaac67454215220696f..826fe0d864f2ebcb388d3d97f6030d450a60fe3d 100644
--- a/components/variations/service/variations_service.cc
+++ b/components/variations/service/variations_service.cc
@@ -929,4 +929,8 @@ bool VariationsService::OverrideStoredPermanentCountry(
   return true;
 }
 
+std::string VariationsService::GetLatestCountry() const {
+  return local_state_->GetString(prefs::kVariationsCountry);
+}
+
 }  // namespace variations